Process of liberating and recovering oil from materials containing starch, proteins, and oil



Patented Aug. '12 1952 rao'cnss on LIBERATINGIYAND RECOVER: 1 V ING OIL FROM MATERIALS CONTAINING, STARCH, PROTEINS, AND OIL Elton n. Darling, Muncie, 111., and William 12.0, Y

Yelland, Washington, D. 0.,assignors to Lauhofi Grain Company, Danville, 111., a corporation of Illinois 'f No Drawing. 1 Application May 10, 1949,

' j p Serial No. 92,521

colai ms. (Cl. 260412.3)

The present invention relates to an improved process for the liberation and recovery of oil fli pm materials containing starch, proteins and The process has particular applicability to the of local over-concentration, would, not disperse treatment of certain cereal products that conthe proteins or attack the starches. Materials Starch, p e n nd'f ty su tances, mainly which could be used under careful control are the oils; the process providing an effective method alkalies, alkaline reacting saltssuch as the alkali for the recovery of. the oil without any delecarbonate, etc., but it-is preferred to employ certerlous efiects upon either the starches or protairi alkaline-reacting materials that contain nitelns contained in the material. Specifically, the trogen, primarily ammonium hydroxide, ammo- PF ay be p 0y d or the recovery of C nium carbonate or one of the ethanolamines, 3 55191 1 g g a i y-g od cts 111 yl g especially the alkaline-reacting monoethanole nven ion may, owever, aso e amine, successfully applied to the treatment of other oil- In essence the 'roeessicomprises suspending m s" mat r a s. as soy an flour, cottonthe material that is to be treated in an aqueous Seed, commmuted peanul'ls andthe llkesolution of an alkali having a low enough pH to One of the outstandlng adva of the avoid dissolving or dispersingthe protein or to g ggiz s figgff 33 g i the F of gelatinize or swell the starch granules contained have to be re nfov d fr m iahe o il by di tilla i gn i i ci e r l tlg i o ure 280 50 1 1228? $155 1 332 2 1122:-

I o a 1 31 1 11 5? are ik to leave an undesirable taste rial that is undergoing treatment, the operation Another advantage is that it avoids the use of being preferably conducteod I ogdinary room presses, such as have been used for the extracgf E tron; 5 2 a tion of oil from cottonseed, etc., thereby propeno 0 say? ou we cults oug viding a residue that lends itself particularly there Is nothmglcntlcal about-such t1-me or temwell to the further separation of the said residue f g't as no 'g requlredat any into unbroken starch granules and a dispersion S age 0 procqdure here Is considers-me of protein, which latter is substantially unde- Saving both m equlpme'nt andgost ofope'ramon' natured and can be separately recovered, as dishas also found F advantageous to closed and claimed in our co-pencling application have present-93mmemulsltynig agent's that-tend Serial No. 87,562, filed April 14, 1949, now U. s. pmduce emulsmn' althwgh they Patent. No. 2,534,249. should be of a type that can subsequently be ren- It is therefore one of the primary objects of dered inefiective, so that the emulsion produced the present invention to provide a process'for the may be readfly .broken and resolved mto sepa" selective separation of the oil and proteins conrable l y 1 aqueous. p H tamed in cereal products The invention will be described in connection A further object is to pre-treat certain cereal 71th the treatment by'product of products which contain 011, proteins, and starch, h dry'mmmg of Said Wproduct having so that the latter two materials may be more efhltherto, Fd merely elatlvely cheap form fectively subsequently separated of feed, it having been believed that the oil, pro- A still further object is to provide a process teinand starch content thereof could not, ecofor the recovery of oil contained in the by-prod-- nomlfmny bei'yesolved and separately recovered I nets of the dry-milling of corn, without adversely T1115 mammal has the ignowmg-Y aver-age afiecting the starch contained in said byfproduct. P 0 so that it maybe subsequently recovered in the V i l' 1 cent form of unchanged starch granules Molsture, "7

Other objects will become apparent from the Dry ba51s 311211375151 V a further description of the present invention Protem hereinbehw; V. Crude fat--. 6.14

.While many alkaline materials may be em- A h -1.90 played for the selective emulsification of the oil Crude fiber; 3.66 contained in the materials treated by the present I V process, providedsuflicient care is used toavoid h degree 0 minu o of t is a erial, solubilization or colloidal dispersion ofthe 'pro- 55 wh h is a p a by-pr du tqi the nakinl; of

tein, and posslble softening or even incipient gelatinization of the starch, yet it has been found advisable to employ such alkaline-reacting materials that, even if accidentally present" in areas hominy grits, is as follows, as shown in the subjoined screen-analysis thereof:

type amenable to the process of the present invention, this would quickly form the necessary amount of ammonium oleate (or its equivalent fatty acid soap of ammonia) to. render unnecessary the actual additionof ammonium oleate. The ammonium oleate present in the eventual emulsion is rendered inactive as the result of the acidification, yielding an ammonium salt and liberating some oleic acid, which is unobjectionable in the finish product. However, if the oilbe subsequently treated with dilute alkaline solutions, as is often done in refining such'vegetable oil, this small amount of oleic Per cent All through 8 mesh. 1 On 10 mesh 0.3- 1.5 5 On 12 mesh 0.5 3.0 On 14 mesh 1.4- 4.7 On 16 mesh 3.8-- 75 On 20 mesh 10.0-11.9 On 24 mesh g 5.7- 7.0 On 28 mesh 10.5-12.6 On 32 mesh 7.7- 9.2 On 35 mesh 6.2- 9.4 On 42 mesh 4.1- 6.2 On 48 mesh 1.6- 5.3 On 60 mesh 2.3- 3.7 On 65 mesh 2.3- 4.9 On 80 mesh 1.3- 3.4 On 100 mesh 3.3- 4.7 Through 100 mesh 20.4-25.7

The actual operation was conducted as follows:

In a 220-gallon conicalbottomed tank were placed 92 U. S. gallons of water and one liter of concentrated ammoniumhydroxide (about 27.9% NHQOH content), whereupon there were added 235 pounds avoirdupois of the above material, having a 14% moisture content. After the added material has'been thoroughly 'wetted, a second liter of ammonium-hydroxide was added. This resulted in a suspension having a total volume of 115 gallons. This slurry was thoroughly agitated by a mechanical mixer for about two hours at the normal prevailing temperature of the building in which the operation was carried out. The alkalinity of the solution was measured during the'operation and was found to vary between about pH 9.75 and 9.85. Under these conditions neither the alkali-soluble or salt-soluble proteins nor the starch of the material was solubilized or appreciably dispersed, but the oil contained'in the material was dispersed throughout the solution in the form of discrete droplets of oil, i. e. an oil-in- Water emulsion was formed. v

Following the just-described steeping operation, the slurry was fed by means of a variable-speed pump at the rate of about 12 to-14' gallons per minute to a suitable centrifuge, such, for ex-.

ample, as the type known in the industry as a Sharples Super-D-Canteri whereby substantially most of the steep solidswere separated from the steep liquor. Theamount-of-such-steep liquor collected was measured at 77 gallons. It had the following analysis: l V

* c.4285 g/lO ml.

Solids Protein 0.1690 g/ 10 ml. Crude fat 0.1067 g/lO ml.

The amount of oil in the steep liquor was found' amount of ammonium oleate in the original solution of ammonium hydroxide as this enhanced the yield, andalso made emulsification of the oil more rapid and complete. However, as there is often a certain amount of free fatty acid in the oil-content ofraw materials of the oil content of' acid would again be removed. The amount of ammonium oleate needed in the process is less than about of 1% on the basis of the material treated. Other equivalent amine salts may be used, such as the ammonium salts or amine salts of fatty acids such as linoleic, etc., or as may be contained in the corn oil. It is generally advisable not to use wetting agents of the type which are not capable of being rendered inert by acids. as these might interfere with the efiectual breaking of the emulsion of oil in water.

In place of using, ammonium hydroxide, the process can be carried outwith ethanolamine, using an amountto yield about the same degree of alkalinity as when using ammonium hydroxide. Likewise, the process may also be carried out with the use of sufficient amounts of ammoniumcarbonate, also at a pH at about 9.75 to 9.85. In the case of monoethanol amine it has been found advantageous to operate at a somewhat high pH, say about pH 10.58. The action of themonoethanolamine can be enhanced by the use of a smallquantity of ethanolamine oleate, instead of ammonium oleate.

The general procedural steps are, however, the same, no matter which particular alkaline-reacting material be'se-lected for the emulsification of the oil.

As the apparatus employed for carrying out the present process is all standard readily obtainable-equipment, it is notdeemed necessary to'illustrate the same.

Accordingly applicants claim as their invention:

1. Process of selectively separating oil from an oil-andprotein-containing comestible material which comprises suspending. said, material in an aqueous solution of an alkaline-reacting nitrogen-containing compound from the group consisting of ammonium hydroxide,'ammonium carbonate and ethanolamine of a concentration suificient to efifect the emulsification of the oil in. said material without materially afiecting the protein, separating the resulting oil-in-water emulsion fromthe residual insoluble materials of said emulsion, breaking the thus. treated emulsion to liberate thefoil therefrom,,andrecovering the latter. u

2. Process of recoveringoilcentained in the farinaceous by -pro duct of the dry-milling of corn, and which contains starch, oil'ancl protein, which comprises suspending said by-p-roduct in anaqueous solution of ;an alkaline-reacting nitrogencontaining compound from the group consisting of ammoniumhydroxide. ammonium carbonate and ethanolamine 'of a concentration suflicient to effect the emulsification of the oil contained in said by-product without'materially affecting the other constituents of said lay-product, thereby forming an emulsion of the oil in the form of an oil in-water emulsion, removing insoluble nonoily constituentsfrom said emulsionr and break- 5 ing the latter to liberate the oil, and recovering the latter.

3. Process of separating a mixture of a protein, an oil and a starch, which comprises subjecting such a mixture to agitation in an aqueous solution of an alkaline-reacting substance of a concentration low enough to efiect the emulsification of said oil into an oil-in-water emulsion but insufficiently high to gelatinize the starch or disperse or dissolve said protein, separating the resulting oil-in-water emulsion from the substantially unchanged protein and starch, liberating the oil from the thus treated emulsion, and recovering said oil.

4. The process as defined in claim 3, in which a small but eflective amount of an acid-inactivatable wetting agent is employed to enhance the an oil-containing farinaceous by-product of the dry-milling of corn which comprises suspending said material in a solution of ammonium hydroxide having a pH of about 9.75 to 9.85 and agitating it therein for about two hours at room temperature, separating undissolved material from the resulting oil-in-water emulsion of said oil, and breaking said emulsion to liberate the oil, and recovering the latter.

ELTON R. DARLING. WILLIAM E. C. YELLAND.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 695,474 McFarlane et a1. Mar. 18, 1902 20 2,376,568 Altschul et al May 22, 1945 2,376,852 Altschul et a1 May 22, 1945 

1. PROCESS OF SELECTIVELY SEPARATING OIL FROM AN OIL-AND-PROTEIN-CONTAINING COMESTIBLE MATERIAL WHICH COMPRISES SUSPENDING SAID MATERIAL IN AN AQUEOUS SOLUTION OF AN ALKALINE-REACTING NITROGEN-CONTAINING COMPOUND FROM THE GROUP CONSISTING OF AMMONIUM HYDROXIDE, AMMONIUM CARBONATE AND ETHANOLAMINE OF A CONCENTRATION SUFFICIENT TO EFFECT THE EMULSIFICATION OF THE OIL IN SAID MATERIAL WITHOUT MATERIALLY AFFECTING THE PROTEIN, SEPARATING THE RESULTING OIL-IN-WATER EMULSION FROM THE RESIDUAL INSOLUBLE MATERIALS OF SAID EMULSION, BREAKING THE THUS TREATED EMULSION TO LIBERATE THE OIL THEREFROM, AND RECOVERING THE LATTER. 